A typical fuel injected internal combustion engine includes a fuel rail which receives fuel from a fuel supply line and supports a series of fuel injectors which discharge the fuel under pressure into the runners of the engine manifold. In a marine engine, the excess fuel not supplied through the injectors is returned to a vapor separator tank which is connected in the fuel supply line and serves to vent vapor to the engine.
In the past, a typical fuel rail assembly has been composed of two separate metal tubes, namely an inlet tube which is connected to the fuel supply line and an outlet tube which is connected to the return line. A metal tube or hose is connected between the downstream end of the inlet tube and the upstream end of the outlet tube. A series of injectors are mounted in the inlet tube and serve to supply fuel to the runners of the manifold.
The connection of the hose between the two tubes requires seals and connecting fittings and constitutes a potential source of fuel leakage.